Apparatus for deaerating liquid



w. s. LLIQTT 1,800,724

APPARATUS FOR DEERATING LIQUID Filed June l, 1925 2 Sheets-Sheet l April 14, 1931.

INVENToR Patented Apr. 14, 1931 WILLIAI B. ELLIOTT, 0F PITTSBUBGH, PENNSYLVANIA 'APIABATUS SFOR.` DEAEBATING LIQUID .Application led June 1,

The present invention4 relates broadly to heat exchanging apparatus, and more particularly to such apparatus as applicable to the deaeration of Water. It is well recognized at the present time that to a very large extent oxygen in water as used in power plant equipment is responsible for corrosion.- Efforts have accordingly been made to effect the removal of such oxygen in lorder to overcome the corrosive actionA 'ofthe water, and the present invention relates to an improved` apparatus for accomplishing this' same result. v

It is recognized by those skilled in the art, that the eifective deaeration of a liquid such as water depends fundamentally upon the creation of the required partial pressures in the zonein which the liquid is undergoing treatment. Where it is desired to effect the separation of the oxygen dissolved in the water, the parti-al pressure ofthe oxygen in the container i'n `which the liquid is being treated should be reduced order` that this resultmay be accomplished. The result desired is attainable in different ways, among which may be mentioned the addition of heat to the liquid for the purpose of producing evaporation thereof to the desired lextent the reduction of pressure for the purpose of producing evaporation of the liquid, or the creation of a vapor condition in contact with the liquid', which vapor condition has the desired relatively low partial pressure due tothe presence of oxygen. Such a vapor condition may be established by the introduction of steam, which theoretically represents the minimum of air content attainable. As a general proposition, it may be stated that water in contact with an atmosphere vaporizes to an extent depending largely upon the temperature of the water and the vtemperature of the atmosphere, as .well as the dynamic conditions of both. In a still atmosphere, whether the water is ina calm or a turbulent condition, the amount of vaporization is dependent upon the temperature. At a given temperature, the amount of water evaporated is a function ofthe amount of agitation -or .turbulency of the water and' the velocity of the atmosphere..

rattained. It will, therefore,

1925. -Serial No. 33,991.

gases rising from the water as `they areI formed whereby a condition of saturation preventing further evaporation cannot be be apparent that in order that the maximum amountof vaporization may occur at a given temperature, it is necessary to produce a maximum turbulency of the water and to cause the atmosphere to sweep over the surface of the water at a velocity as high as possible.

In accordance with the present invention, advantage is taken of the creation and maintenance of the desired vapor or partial pressure conditions in the zone in which the liquid is undergoing treatment, and also of the advantages of' increased vaporization produced by contact between a travellin of gas at a high velocity and a body o? in turbulent condition. l

In the accompanying drawings there is shown, for purposes of illustration only, certain preferred embodiments of the present invention, it being understood that the drawings do not define the limits of my invention as changes nthe construction and operation disclosed therein may be made without departing either from the spirit oi the invention, or the scope of my broader claims.

In the drawings- Figure l is a vertical sectional view, partly in elevation, of onel form of apqaratus embodying the present invention on t e line I-Iof Fig. 2.

Fi re 2 is a vertical sectional view on the line II-II of Figure 1 looking in the direction of the arrows. v

Figure 3 is a view similar lto Figure 1, on the line III-III of 4, illustrating however, a slightly modifie embodiment of tlpresent invention;

- 1 the line IV -IV of Figure 3 looking in the direction of the arrows; and

Fi re 5 is a transverse sectional a re uced scale,l 4, looking in the direction of the arrows.

It has heretofore been proposed 'in the view, on

bodyv Wateri re 4 is a vertical sectional viewl on etl on the line V-V of Figure a .art to which the present invention relates, to providefapparatus for separating gases I from liquid, comprising a heater in which the water and vapors pass amon a series of pans and sprays in a counter ow dlirection. The result of heaters ofl this character as heretofore designed, however, has been an actual penetration by the air and gas released in one stage with the water in `another stage. Thus re-absorption ofthe -treleasedair and gases' has been inevitable by reason of\ the fact that the gases have been caused to pass through the streams of water' dropping from pan to pan. With such apparatus there has been obtained deaeration in the last stages, but this has which is preferably maintained in an agifV tated o turbulent state so as-to sweep away vapors and gases arising from the liquid,V

have` not been lpermitted to pass through the body of liquidl fallin from one agitatt1on further contemplates the treatment of ing device to another. he present invenwater in a plurality of di'ii'erent stages, the vapors released in some of the laterA stages being utilized as a heating medium in some vof the earlier stages, with a consequent condensation of the vapors so that there is no substantial vheat loss .of the apparatus.

during the operation In the vembodiment of the invention illustrated in Figures 1 and 2, there is provided a container 2 having an upper vapor space and a lower' liquid receiving and -storlng space. Extending into the vapor space'is a liquid inlet 3 delivering to a distributing device 4 which in turn overflows onto a series of agitating devices herein illustrated as comprising oppositely disposedl pans or tra s 5. As illustrated, these pans are preferably so constructed as to provide a rough path of travel for the water whereby the` water during its passage thereover is main' tained inl an agitated or turbulent condi-.

tion and at the same time exposed over a comparatively large surface. This water passes successively over the trays in av downward direction, finally being received byfthe liquidv storage space at the bottoml ofthe container from which it may be withdrawn as required for use through an outlet connection 6. The ilow of water into the container may be automatically controlled vin accordance with demand for deaerated -water by providing the inlet 3 with a regulating valve 7 adapted to be operated inl any desired manner, as lfor example, by

means of a oat 8 operated upolnvariations in the level of liquid in the storage space .of the container.4 With such a construction,

as the liquid level' lowers,the valve 7 will be opened to a. greater extent topermit `the entry of more water, while' as the liquid.

level rises in thel Astorage spacethe reverse action with respect to the valve 7 will take place.- In this manner the apparatus is autoi matically operated in accordance with the demands vof the user, a supply of deaerated liqued always being available.

` For the purpose of supplying heat to the i water, there may be provided a heater -9 of the instantaneous type, embodying coils 10 through which the water flows in such man- 4 ner as to be heated to the desiredgtemperw,

ture by the flame produced by a burner'll.

Ordinarily, these burners are of the gas type having a valve 12 adapted to be connected to the water system in such manner that .an

increase of flow through the apparatus will produce a correspondingly greater increase in the flow of gas. This maybe accomplished by utilizing -a pressure. `operated water valve 13 having a connection14 with the gas valve in such mannerthat the gas valve is automatically controlled as desired.

By initially setting the valvesY as determined in order to produce the required temperature conditions, it will be `'apparent that oog.

thereafter-definite conditions will be mainlv tained with respect to temperature, as the amount of heat supplied. will be proportional to the amount otwater.

In actual operation, when water` is withdrawn through the connection 6, water will be supplied to the inlet 3, this water having been previously heated to the exact temperature determined' by vthe setting of the valves. The heated liquid will iow downwardlyover the pans or agitating vdevices 5 in a turbulent condition. During this travel of the water there will be effected the release of vapor, air and gases. The 'amount of evaporation obtained will be greater than is obtained with ordinary heatersqfor the reason, as before pointed out, that the wa' tenismain-tained in a turbulent condition. With the construction illustrated, the air, gasesand vapors releasedV in the lower stages will pass seriallyupwardly through the upper stages. `During this passagewhey will sweep over the liquid on the agitating de vices at a comparatively high velocity in' such manner as to sweep away any 'gases and vapors that ma arise from the water during its passage t ereover. `The path of travel of the gases and vapors as indicated by the arrows A is, however, different4 from the path of travelofthe water, so as tormake it unnecessary vfor the previously released gases to again pass through a body of water in suchmanner that they may become r e. absorbed. This may be accomplished by water are all obtained. These factors all cooperate to produce within the vaporspace of the container partiaF pressure conditions ideal for therelease of contained air -from the water. This released air, together with any vapor which may not' have become condensed during fpassage over the upper devices, escapes rom the container through a vent 15.

In Figures 3.and 4 of the drawin s there is illustrated a slightly modified orm of the apparatus, parts correspondin to parts already described being, however, esignated by the same reference characters having a prime aliizedfthereto.A In accordance with this embodiment of the invention,"heat is supplied-to the container by means of a steam .inlet 16.- -The vent .1n turn cooperateswith acondenser` 17 having ,an air ofi'- through the condenser. This downwardly v leased from therefrom-with the vapor are'not permitted.

take 18., The water to be treated -flows first through the condenser by means`of an inlet 19 and thence through an outlet 20 and valve 7. to the inlet 3. With such a construction, the water entering the apparatus has been preheated to an extent determined by the heat of the vapors and gases passing partiall heatwater venters the apparatus an flows therethrough over' the agitat- 5 in the manner before deing devices scribed.v The steam admitted through the colder water as the steam comes into contact with it. Anysurplus steam will pass into the condenser lalong with the air 'and I n't e case of extremely eicient heaters, it is possible to assume a condition in a structure of the character illustrated in Figlires 3 and 4, in which the liquid in the liquid storage space of the container reaches a temperature appromately equal to that of the entering steam. In such a case, the supplied steam would itself determine the partial pressureexisting above the liquid,

possibility of contact and in view of the relatively low partial pressure of the air, separation of oxygen dissolved in lthe water would be insured. Even with such a condition of temperature in the lower portion of the apparatus, however,

evaporation would take place as the liquid flows over some of the upper trays, and this evaporation `will be effective for maintaining the desired conditions for deaeration. At

`the same time, the velocity of the vapors and gases passing over the liquid insures the prompt sweeping away 'of the released air without any possibility of any reabsorption thereof. with a Vheater of this type the alnount of steam supplied is proportional with the amount of-work being done by the heater, so that substantially 4constant temperature conditions in the heater can be automatically maintained irrespective of variations in the iow of water therethrough.

It will be observed that in both types of apparatus there is a continuous and progressive treatment of `successively admitted water vunder such conditions that water in a later stage of deaeration is not mixed with water in a materially earlier stage of deaeratlon, while 'water'in an earlier stage of deaeration is subjected to the action of vapors and gases from a later stage without possibility of re-absorption of the released air, or the between vapors and 'gases between an earlier stage with water at a later stage. As the water is continuously and progressively treated inI the manner referred'to, it is brought into contact with conditions of temperature and pressure such as to produce the desired results, such conditions being continuously maintained,f at least with respect toa predetermined minimum. The invention contemplates the continuous bringing into action'of an amount of heat necessary, at least with respect to the minimum referred to -to produce a change of. phase of the liquid to an extent to eiiect the release of all of the air therefrom. This change of phase, as pointed out, takes place under ideal conditions by reason of the continuous control of pressures, both total and partial, and of temperature by reason of the inter-relation between the amount of water supplied and the amount of heat.

Itis desirable from the standpoint of most eihcient results to havel the water leave the last agitating devices at a temperature at least substantially corresponding to the boiling point of the water or thepressure obtalning in the liquid storage space, and the invention contemplates temperature conditions such that this. operation may be obtained.

The advantages of the present invention arise from the provision of a method and apparatus for eecting deaeration of water under such conditions that re-absorption of the It will be understood that,

released air and prevented.

Further advantages of the invention arise from the .provision ofv an apparatus capable other gases iseiectively of maintamingthe water in a .turbulent or.- agitated condition and in contact with gases container having. a liquid space and la vapor I' so.

space, a plurality of agitatingl tra s in` the vapor space with adjacent trayso set relai) tive to each other on each of two sides, means forA supplying the liquid to be treated to the upper tray whereby itis caused to pass.. 4downwardly. over one of the `offset sides of each of the trays in series, and a separate ow path for the released ain and gases extending over each of the other of the offset sides of the agitating trays but-not 'intersecting the iiow path of the water'thereov'er, said agitating trays having flow path con-tour to maintain thewater in a turbulent film-like condition during its passage thereovensubstantially as described." r2. In a deaerating appartus, a container, and trays therein each-having two free sldes only'with the remainder of the tray perimeter closed, said trays beingdownwardly -inclined to cause the passa e of water down-l wardly over one lof the sldes of each tray and the-passage of the vapors and gases upwardly around .the otherfsideof eachof said .trays,.substantially as described.

3i. In a deaerating apparatus, a container, and trays therein each having twov free sides only with the remainder of the tray perim- :feter closed, said trays Ibeing downwardly in# 'clined' to cause the passage of'water downwardly over one of the free sides of each. tray and the passage of the vapors and gases upwardly around the other free side Y of each of said trays, the sides of said trays beingv offset and so arranged as to provide a How of water which is .substantially normal to the How ofvaporsand gases, substantially as described. y

said container compelling a vaporand gas.

' normal thereto, substantially as described.

--oA c direction and -a water flow transverselyV 4. In a deaeratlng apparatus, 4a container,

a source of watersupply therefor, means in.

flow transversely of the container inV one direction and a water iow transversely thereof in another direction substantially l5. In a deaerating apparatus, a container, a source of water supplytherefor, means -in .said container compelling vapor and gas.

How transversely o the container in one thereof inl another-,direction substantially an irregular my hand.

- 6. Ina deaerating apparatus,`a container and trays therein each having two free sides and the remainder .of the tray perimeter' closed, said trays each being downwardly inclined and arranged-with the closed and open sides of successive trays alternating o cause the passage of water downwardly over one of the free sides of each tray and the .passage of the vaporand' gases upwardly around the other sides of said trays..

17. In a water treating apparatus, superimposed trays each'having .two free sides and the remainder of the tray perimeter closed, alternate trays havingcorrespondin f sides free and corresponding sides close with the intermediate trays offset relatively thereto. Y Y

8. In a water treating apparatus, superimposed trays each having two free sides -and the rest of the side edge closed, alternate trays having correspondingsides 4free and corresponding sides closed with the in.-

termediate trays offset relatively thereto,

said trays being constructed to' continuously agitate the water during its passage therecontainer having a liquid space and a vapor space, a plurality of agitating trays in the vapor space arranged .in'sta gered relation,

closed. to, provide a separate flow path for the released air and gases extending overthe agitating devices but not intersecting the ow path thereover, substantially as described.

A.10. Deaerating apparatus comprising a container having a liquid space and a vapor space, a plurality of agitating trays in the vapor space arranged in staggered relation, means for supplying the liquid to be treated to the" upper tray whereby it is caused lto pass downwardly oyer the trays in series, the. opposite sides of adjacent trays being closed to provide aseparate iow path for the released air and gases extending over the agitatin devices but not intersecting the How pat 'thereover, said agitating devices: being constructed to maintain the water in turbulent condition in passage s. ELLIOTT.

normal thereto, sadmeans comprising superimposed trays each having two free sides,

` substantially as described.

9. Deaerating f apparatus comprising vav 

